Wechselwirkung von Morphaktin mit gibberellinsäure bei ganzen Pflanzen und bei der Stecklingsbewurzelung

The methyl-ester of 2-chloro-9-hydroxyfluorenole-9-carboxylic acid (Chlorflurenol-Methyl =CFM) enhances the elongation of intact plants ofColeus blumei and induces leaf curvatures and an anormalous abscission of the youngest leaves. In long-time-experiments (3–4 month), CFM induces increased outgrowth of the axillary buds including leaf deformations and abscission of organs on the originating shoots. CFM stimulates the adventitious root formation of cuttings fromHelianthus, Phaseolus, andColeus. It is shown inColeus cuttings that an inhibition of root formation precedes the stimulation of root formation. Gibberellic acid does not influence any one of CFM-induced effects. Therefore morphactins are not GA₃-antagonists. TIBA qualitatively causes the same effects as CFM. Therefore it is possible that the mechanisms of actions of both substances are similar.     

Genetic mapping of the polycystic kidney gene,pcy, on mouse chromosome 9

The murine polycystic kidney disease gene,pcy, is an autosomal recessive trait located on chromosome 9. To determine the genetic locus ofpcy, 222 intraspecific backcross mice were obtained by mating C57BL/6FG-pcy andMus molossinus. Restriction fragment length polymorphism analysis of 70 of the 222 backcross progeny showed thatpcy, dilute coat color (d), and cholecystokinin (Cck) were located in the orderd—pcy—Cck from the centromere. Simple sequence repeat length polymorphism analysis of DNA of all 222 backcross mice was carried out using four markers which were located near the central regions ofd andCck. One and eight recombinations were detected betweenD9Mit24 andpcy and betweenD9Mit16 andpcy, respectively. However, no recombinant was observed amongpcy, D9Mit14, andD9Mit148. These findings strongly suggest thatD9Mit14 andD9Mit148 are located near thepcy gene and are good markers for chromosomal walking to this gene.     

Silica Deposition in Some C3 and C4 Species of Grasses, Sedges and Composites in the USA

We report new information on silica deposition in 15 plant species,including nine grasses, two sedges and four composites. Thesilica depositional patterns found in seven of the grass speciesindicate that they are C₄ plants. However the festucoid grassCortaderia selloana is a C₃ plant with long leaf trichomes andoval silica structures in the leaves. In contrast the panicoidC₄ grasses Chasmathium latifolium, Chasmathium sessiflorum,Imperata cylindrica, Panicum repens, Panicum commutatum andSetaria magna, all produce dumb-bell-shaped silica structuresin the leaves. The chloridoid grasses Spartina patens and Spartinacynosuroides have saddle-shaped structures and no dumb-bellor oval shaped ones. The sedges Rhynchospora plumosa and Scirpuscyperinus were found to have oval phytoliths and may be C₃ plants.Our examination of these and other grasses strongly suggeststhat C₄ grasses tend to produce the same type of silica cells.Grasses and sedges with C₃ type photosynthesis tend to produceoval silica structures. The composite Grindelia squarrosa andsunflowers Helianthus angustifolia, Helianthus atrorubens andHelianthus tuberosus absorb relatively small amounts of siliconand larger amounts of calcium, where both elements deposit inleaf trichomes. We found no clear indicator for the C₃ sunflowersor C₄ types in the Asteraceae. Helianthus tuberosus leaves havemany trichomes on the adaxial surface. These trichomes havea higher concentration of silica than the surrounding leaf surface.Helianthus tuberosus leaves had much higher ash and silica contentsthan those of Helianthus angustifolia and Helianthus atrorubens.The composite Grindelia squarrosa has a usual deposition ofsilica in the basal cells around the guard cells. Silica depositionoften reflects the surface features of a leaf. An exceptionis Scripus cyperinus where the silica structures are deep inthe tissue and do not reflect the surface configurations. Theinforescence of Setaria magna had a 14.64 silica content. Thetufts of white, silky hairs characteristic of Imperata cylindricainflorescence have no silica. C₃ and C₄ plants, silica and ash content, scanning electron microscopy, energy-dispersive X-ray analysis, silicon distribution, spectra of elements in plants, trichomes, silica fibres, phytoliths     

Flavonoid chemistry of the endemic species of Myrceugenia (Myrtaceae) of the Juan Fernandez Islands and relatives in continental South America

Twenty-one flavonoids were isolated from the leaves of two endemic species ofMyrceugenia on the Juan Fernandez Islands,M. fernandeziana andM. schulzei, from two related species from Brazil,M. campestris andM. rufescens, and from five species from continental Chile,M. colchaguensis, M. exsucca, M. lanceolata, M. pinifolia, andM. rufa. A phenetic analysis was used to evaluate chemical similarities.Myrceugenia campestris andM. rufescens appear most closely related to each other based on flavonoid profiles, and they are also different from the other seven species. The two endemic species in the Juan Fernandez Islands,M. fernandeziana andM. schulzei, group with the continental Chilean species. The former is most closely related toM. lanceolata, and the latter clusters withM. exsucca, although somewhat distantly. The results suggest that the two Juan Fernandez endemics are derived from two introductions from the Chilean continent and not from immigrants from the eastern side of the Andes.     

Studies in the cyperaceae of Thailand

Ten species ofCarex and one species ofKobresia from Thailand are taxonomically discussed, and some new range extensions into Thailand are noted. Described as new areCarex subinclinata andC. thailandica, both belonging to the sectionIndicae, andC. speciosa ssp.latifolia of the sectionRadicales. Two new combinations proposed areCarex helferi ssp.mapanifolia, andC. speciosa ssp.platyrhina.     

Sesquiterpene lactones from Helianthus grosseserratus

The isolation is reported of six new sesquiterpene lactones based on the eudesmanolide, trans, trans-germacradienolide and heliangolide skeletons from Helianthus grosseserratus Martens. The diterpenes grandifloric, 17-hydroxy-ent-isokaur-15-enic and ciliaric acids and the flavones hispidulin and pectolinarigenin were also found.     

A new species ofScymnodalatias from the southern oceans,and comments on other squaliform sharks

Scymnodalatias albicauda sp. nov. is described from two specimens taken at high latitudes (45°S and 49°S). It is distinguished fromS. sherwoodi, only known species of the genus, by having white markings on the caudal fin, the second dorsal posterior tip almost reaching the upper caudal fin, shorter snout and head, smaller eye and larger fins. Relationships ofScymnodalatias to the generaScymnodon, Centroscymnus, andZameus are discussed, based chiefly on dermal denticle structure.Scymnodalatias andZameus uniquely share transverse ridges on their dermal denticles, and on this character they are treated as sister-groups. Comments on the above genera,Z. squamulosus and some species ofScymnodon are made to clarify their systematic status. As a result, it is proposed thatScymnodon includesichiharai, macracanthus, plunketi, andringens, thatCentroscymnus includescoelolepis, crepidater, crypt acanthus, andowstonii, and thatZameus includessquamulosus.     

Diurnal changes in chlorophylla fluorescence and carotenoid composition inOpuntia ficus-indica,a CAM plant,and in three C3 species in Portugal during summer

Summary Diurnal changes in chlorophylla fluorescence were determined in four species, differing in life form, in Portugal during the summer of 1989. These includedOpuntia ficus-indica, a CAM plant, andHelianthus annuus, Ficus carica andArbutus unedo, three C₃ species. Steady state fluorescence yield,F _S, and maximum fluorescence yield,F _M′, were determined at different times of the day. Using the model of Genty et al. (1989), the photon use efficiency of photosystem II electron transport,φ _e, was calculated from (F _M′−F _S)/F _M′. Diurnal changes in relative rate of non-cyclic electron transport through photosystem II,J _e, were derived by multiplyingφ _e by the incident photon flux density (PFD). WhenJ _e, determined for each species for various points in time throughout the day, was plotted against corresponding values of PFD, the light response curves obtained showed thatJ _e was linearly dependent on PFD in low light and approached saturation in high light. The highest values ofJ _e were observed inHelianthus annuus, followed byOpuntia ficus-indica, Ficus carica andArbutus unedo. The proportion of the xanthophyll zeaxanthin to total carotenoids, determined around noon, was inversely related to maximum rates ofJ _e.     

Inheritance and linkage analysis of ten enzyme and blood protein loci in the Japanese brown frogRana japonica

In order to clarify the genetic linkage groups of the Japanese brown frogRana japonica, and compare them with those of other vertebrates, the inheritance of 10 enzyme and blood protein loci was examined in 267 offspring derived from 18 crosses using 10 males heterozygous at these loci. Most of the segregation tests exhibited no significant deviations from the expected normal Mendelian ratios. Of 32 pairs of loci tested for linkage, 29 pairs showed independent assortment in all crosses examined. In the three other locus pairs, betweenADH-1 andAlb, IDH-1 andHb-1, andLDH-B andMPI, all offspring analyzed were parental, and there were no recombinants. These three linkage groups comprising six loci were thus established inR. japonica, whereas no linkage between the other four loci,AAT-1, ADA, GPI, andPEP-A, was observed.     

Lectotypifications of infrageneric taxa in Psoraleeae (Leguminosae: Papilionoidae)

Psoralea (Leguminosae: Papilionoidae) sectionsAxillariflorae, Capitatae, andSpicatae, andPsoralea subseriesSparsiflorae, Fasciculatae, Spicato-capitatae, andSpicato-racemosae are lectotypified.     

Molecular traits to elucidate the ancestry of Helianthus x multiflorus

The triploid perennial Helianthus x multiflorus L. is a beloved garden ornamental, but its phylogenetic origin has long been a source of discussion. Sequence comparison of genes involved in the biosynthesis of the sesquiterpene lactones was used to identify the common sunflower Helianthus annuus L. and the diploid taxon Helianthus decapetalus L. as the most likely parental combination in the origin of the triploid hybrid species. A pair of deletions (22 and 26 bp in length) in an intron part of the germacrene A synthase 1 gene differentiated the diploid from the tetraploid karyotype of H. decapetalus. The same deletion was found in one of the two alleles (299 bp in length) in H. x multiflorus, whereas a second allele (350 bp in length) showed a very high similarity with the sequence found in H. annuus. Quantification of the two amplification products in H. x multiflorus showed a higher concentration of the larger amplicon thus suggesting that H. annuus has contributed an unreduced genome to the hybrid. Comparison of variable regions of the cpDNA showed highest identity of H. x multiflorus with cpDNA sequences of the diploid H. decapetalus. This suggests that H. decapetalus served as the maternal parent in a cross with H. annuus to produce H. x multiflorus.     

Mutations affecting extracellular protease production in the filamentous fungusAspergillus nidulans

The extracellular proteases ofAspergillus nidulans are known to be regulated by carbon, nitrogen and sulphur metabolite repression. In this study, a mutant with reduced levels of extracellular protease was isolated by screening for loss of halo production on milk plates. Genetic analysis of the mutant showed that it contains a single, recessive mutation, in a gene which we have designatedxprE, located on chromosome VI. ThexprE1 mutation affected the production of extracellular proteases in response to carbon, nitrogen and, to a lesser extent, sulphur limitation. Three reversion mutations,xprF1, xprF2 andxprG1, which suppressxprE1, were characterised. BothxprF andxprG map to chromosome VII but the two genes are unlinked. ThexprF1, xprF2 andxprG1 mutants showed high levels of milk-clearing activity on medium containing milk as a carbon source but reduced growth on a number of nitrogen sources. Evidence is presented that thexprE1 andxprG1 mutations alter expression of more than one protease and affect levels of alkaline protease gene mRNA.     

Glutamatergic elements in an excitability and circumnutation mechanism

In plants, an electrical potential and circumnutation disturbances are a part of a response to environmental and internal stimuli. Precise relations between electrical potential changes and circumnutation mechanisms are unclear. We have found recently that glutamate (Glu) injection into Helianthus annuus stem induced a series of action potentials (APs) and a transient decrease in circumnutation activity. A theoretical explanation for this finding is discussed here taking into considerations data about the ion mechanism of AP and circumnutation as well as about the metabolic and signaling pathways of glutamate and their possible interactions.Key words: action potential, circumnutation, elongation, glutamate, Helianthus annuus, plant movement     

Furanoheliangolides from helianthus schweinitzii

The two furanoheliangolides budlein A and a new compound, °^4,15-isoatripliciolide tiglate, were isolated from the hexaploid sunflower Helianthus schweinitzii. Budlein A has been previously isolated from H. angustifolius, a diploid species suggested as a possible progenitor of H. schweinitzii.     

TWO NEW SPECIES OF THE LICHEN GENUSIMMERSARIA(PORPIDIACEAE)

Immersaria olivacea, its lichenicolous fungusPolycoccum decolorans, andImmersaria mehadianaare described as new species from Spain and Romania, respectively. A new combination,Immersaria cupreoatrais proposed, and a revised concept of the generaBellemereaandImmersariais supplied.